Compatibility, morphology, and crystallization behavior of compatibilized β-nucleated polypropylene/poly(trimethylene terephthalate) blends

摘要

β-Nucleated polypropylene (PP), uncompatibilized β-nucleated PP/poly(trimethylene terephthalate) (PTT), β-nucleated PP/PTT blends compatibilized with maleic anhydride (MA)-grafted PP (PP-g-MA), and styrene-ethylene-propylene copolymer were prepared with a twin-screw extruder. The morphology, compatibility, crystallization characteristic, melting behavior, and crystallization kinetics were investigated. The result shows that β-nucleated PP was incompatible with PTT, and the addition of the two compatibilizers decreased the interfacial tension between β-nucleated PP and PTT; this led to improved dispersion and strengthened interfacial bonding in the blends. PP-g-MA had a better compatibilization effect. All of the researched β-nucleated PP/PTT blends contained β crystals of PP, and the compatibilizers exhibited synergistic effects with the β-nucleating agent to further increase the content of β crystals. Nonisothermal kinetic analysis indicated that Mo's method described the nonisothermal crystallization behavior of the β-nucleated PP/PTT blends satisfactorily, and the Avrami approach could only describe the early stage of the crystallization appropriately, whereas the Ozawa method failed to have the same effect.